Node containing text?
No such composite node exists (I am assuming you want it for that pane, but most of these are in Material and Texture too). Here are all the different types of composite nodes in Blender.

Types of Composite Nodes
This section is organized by type of nodes, which are grouped based on
similar functions:

Input - Adds something to the node map, such as an image or a value.
Output - Displays the result in progress as a small image.
Color - Manipulates the colors of an image.
Vector - Manipulate the intensities and reflections of an image
Filters - Process the image to enhance it, working on adjacent pixels.
Converters - Separate the image into its component video, or convert formats.
Mattes - Generating mattes to mask off areas of an image.
Distortion - Changing the shape of the image.
Groups - User-defined groups of nodes.


At most you can change the name of the label.